Clamping or spreading tool

ABSTRACT

A clamping and/or spreading tool comprises a drive for displacement of a push or pull rod to which a movable jaw is fixed with respect to a support carrying a stationary jaw in longitudinal direction of the push and pull rod, the drive comprising a torsion spring and being adapted to enter torque transmitting engagement with the push or pull rod for displacement of the same.

RELATED APPLICATIONS

This application is a continuation of and claims priority from U.S.patent application Ser. No. 11/936,439, filed on Nov. 7, 2007, which isa continuation of and claims priority benefit from U.S. patentapplication Ser. No. 10/576,091, filed on Apr. 11, 2006, which is a U.S.national phase of PCT EP/2004/014179 filed on Dec. 13, 2004, whichclaims priority benefit of: DE 103 58 301.7 filed on Dec. 12, 2003; DE103 58 296.7 filed on Dec. 12, 2003; DE 103 58 302.5 filed Dec. 12,2003; DE 103 58 303.3 filed Dec. 12, 2003; DE 103 58 304.1 filed Dec.12, 2003; and DE 103 58 291.6 filed Dec. 12, 2003, the specifications ofwhich are hereby incorporated by reference.

BACKGROUND

1. Field of the Invention

The invention relates to a clamping and/or spreading tool comprising adrive for displacement of a push or pull rod to which a movable jaw isfixed with respect to a support carrying a stationary jaw, inlongitudinal direction of the push or pull rod.

2. Description of the Related Art

It is known to provide in particular clamping and/or spreading toolswith a stepping gear transmission to cause stepwise approach of themovable jaw to the stationary jaw and, at the same time, apply theclamping forces required between the clamping jaws. Such a clampingand/or spreading tool is known from DE 39 17 473 which comprises astepping gear transmission of which the step width per actuating strokeof a drive arm is sufficiently great and a relatively small actuatingforce can give rise to clamping forces when clamping an article which isgrasped between the jaws. A clamping and/or spreading tool of this kindhas proved very successful in everyday use.

U.S. Pat. No. 6,568,667 discloses a clamping and/or spreading toolcomprising an identical stepping gear transmission and an additionalquick-lock drive which operates to close the clamping jaws, i.e. toshift the movable jaw towards the stationary jaw when a draw-back lockpreventing displacement of the push or pull rod contrary to the advancedirection of the stepping gear transmission is actuated. The prime moverof the quick-lock drive is embodied by a helical compression springacting between points of attachment at a side of the support remote fromthe movable jaw. It is a disadvantage of this quick-lock mechanism thatmuch space is required to offer the quick-lock mechanism the path neededfor unfolding the driving power stored. As the compression springassembly needs a long drive path for the driving power to unfold,clamping and/or spreading tools of this kind have not only a great axialextension but also great weight, making such tools unwieldy to handle.Moreover, nonlinear power output accompanies the helical compressionspring, in other words great thrust occurs at the beginning of theclosing motion, diminishing gradually in the course of the closingmotion. Above all, the known drive bears a risk of injury since themovable jaw closes explosively.

SUMMARY

It is an object of the invention to overcome the disadvantages of thestate of the art, providing especially a drive for a clamping and/orspreading tool for especially continuous displacement of a push or pullrod, the dimensions in space of the clamping and/or spreading tool beingsmall and the weight lower, and especially uniform closing motion withespecially a uniform closing force being warranted.

A drive wheel adapted to be driven in rotation is provided forcooperation with the push or pull rod. As this rotatable drive wheeldoes not need a drive or acceleration path extending in longitudinaldirection of the push or pull rod, the axial dimension of the clampingand/or spreading tool according to the invention is clearly reduced incomparison with known clamping and/or spreading tools having acorresponding mode of operation. Not only the weight is reduced as aconsequence of the small dimensions but also the handling of theclamping and/or spreading tool is facilitated since its actuation,especially that of a stepping gear transmission is not obstructed byportions of the push or pull rod projecting far beyond the support.Especially when space is tight where a clamping or spreading tool is tobe used and a handle of the stepping gear transmission is restricted,the clamping and/or spreading tool according to the invention is mucheasier to manipulate than the known ones. While the known high speedclosure mechanism including a compression spring presents further riskof injury to the operator in that he/she may get parts of his/her bodysqueezed between the coil windings and the propelling forces arereleased explosively, such potential risks can be eliminated by themeasure according to the invention. According to the invention, thedrive wheel is operationally coupled to a torsion spring for rotationaldriving. The torsion spring is a mechanical prime mover having amechanical energy reservoir. In comparison with an electricalalternative, this mechanical prime mover has the advantage of not beingdependent on electrical power supply. The wheel driven by the torsionspring, according to the invention, is adapted to enter into torquetransmitting engagement with the push or pull rod to displace the same.The drive wheel can be engaged with the push or pull rod to transmittorque.

Preferably, the drive wheel is arranged directly in contact with thepush or pull rod, especially for engagement in friction or force lockwhereby the drive wheel rolls off the push or pull rod so as to transmitthe torque. The drive wheel is coordinated with the push or pull rod insuch a way that, operationally, the rotary motion of the drive wheel canbe converted into translatory motion for the push or pull rod. With thegear member thus designed as a drive wheel, the motor may be embodied bya torsion spring having especially only a single rotary drivingdirection. A suitable gear arrangement must be interposed between thetorsion spring and the structural element which converts the rotationalmovement into translatory movement so as to guarantee displacement ofthe push or pull rod in both longitudinal directions. When using anelectric motor, displacement of the push or pull rod in bothlongitudinal directions can be accomplished simply by reversing thedirection of rotation through reversal of polarity of the electricmotor. The drive wheel preferably rolls off the push or pull rod suchthat the push or pull rod is shifted in substantially rotation-freemovement, i.e. pure translatory movement.

In a preferred design of the drive according to the invention as atorsion spring motor, a mechanism is provided for changing the directionof displacement of the push or pull rod. The change may occur as achange from closing displacement to opening displacement and/or viceversa. The mechanism preferably comprises a rotation alternator designedto invert the torque transmitted to the push or pull rod by the drivewheel.

With a special design of the rotation alternator, a gear component forconverting rotary motion into preferably purely translatory motion isdisposed between the drive wheel and the push or pull rod. The rotatablegear component is adapted for an engagement with the drive wheel inwhich torque is transmittable, and to be disengaged from the same. Withthe gearing configured for torque transmitting engagement, the push orpull rod can be displaced in one direction, whereas the oppositedirection of displacement is offered when the gear component is in aposition in which engagement with the gear member is lifted. The gearcomponent can be changed manually by the operator from an activeposition for converting rotary motion into translatory motion into apassive position without conversion of rotary motion.

A special design of the mechanism for reversing the direction ofdisplacement comprises an intermediate gear member which is adapted tobe coupled operationally with the drive wheel and the gear component.This coupling is mutually exclusive. For instance, with a firstconfiguration of the gearing for a first direction of displacement, thedrive wheel drives the gear component through the intermediate gearmember. With a second gearing configuration, the drive wheel drives thegear component directly, without intermission of the gear member.

The intermediate gear member is adapted to enter into form- orforce-lock engagement, especially rolling-off engagement with the drivewheel and/or the gear component. That may be accomplished by frictionalcontact or by a meshing teeth connection.

In a further development of the invention, the mechanism for reversingthe direction of displacement is provided with a switch means forselecting the direction of displacement, especially a switch means whichcan be actuated manually by the person handling the clamping and/orspreading tool. The switch means especially may be provided in the formof an operating member or actuator by which to activate and/ordeactivate the rotation alternator.

Especially in a clamping and/or spreading tool of known structurecomprising a stepping gear transmission and a draw-back lock to preventdisplacement of the push or pull rod contrary to the advance directionof the stepping gear transmission according to the invention, thedraw-back lock may be drawn upon to serve as an operating member oractuator of the switch means.

The operating member or actuator comprises an especially non-actuatedposition to prevent displacement of the push or pull rod in closingand/or opening direction. If the actuator is embodied by the draw-backlock of a stepping gear transmission the blocking position is anon-actuated position of the draw-back lock. On the one hand, shiftingof the push or pull rod is blocked functionally against the advancedirection of the stepping gear transmission, i.e. for opening theclamping jaws.

The actuator may have a first release position to permit rotationalmovement for a first direction of displacement. Especially with thedraw-back lock serving as actuator, this first release position may beobtained by lightly actuating the lever of the draw-back lock especiallyinto an intermediate position at which the blocking function iscancelled and the push or pull rod may be shifted contrary to theadvance direction of the stepping gear transmission.

The actuator, moreover, may have a second release position, especiallyan end or stop position, to permit rotational movement for a seconddirection of displacement. Especially with the draw-back lock serving asactuator, this second release position may be obtained by fullyactuating or pressing down the lever of the draw-back lock, i.e. up tothe stop. Hereby, for instance, the above mentioned rotation alternatorcan be activated, thus allowing the push or pull rod to be shifted inopposite sense to the first direction of displacement, for example, foropening the clamping jaws.

An adjusting member may be provided especially with a mechanism forreversing the direction of displacement and comprising a gear componentand an intermediate gear member, to either adjust the gear component orthe intermediate gear member so that one of the two will establish orbreak form-lock or force-lock, especially roll-off engagement with thedrive wheel.

Another aspect of the invention, dependent on or independent of theabove mentioned subject matter of the invention, relates to a clampingand/or spreading tool with which the ergonomics of the clamping and/orspreading tool are to be improved, especially a drive for a clamping orspreading tool for especially continuous displacement of the push orpull rod is to be provided, the dimensions in space, especially inlongitudinal direction, and the weight are minimized, and uniformclosing motion with especially uniform closing force is offered.

According to the invention a means is provided for generating pullbetween the push rod and the pull rod and the support. The dimension ofthe support and its casing can be utilized by the measure of theinvention to make use of a drive path for releasing drive energy.Alternative drive paths are not needed, as with the known quick-lockmechanism. Therefore, the clamping or spreading tool according to theinvention has much smaller dimensions and also substantially lowerweight. Moreover, pulling means in general release the driving forceless abruptly because of their elasticity, whereby the risk of injury isreduced.

In the case of a preferred design, the small space requirement is due,above all, to a tension spring, especially a torsion spring. The tensionspring has points of application of force both at the support and at thepush or pull rod or at the movable jaw.

To permit holding especially large articles between the clamping jaws,the tension spring is releasably attached to the push or pull rod or tothe movable jaw so as to be readjustable to a position closer to thesupport and secured once more. In this manner tension springs of shortpulling distances may be drawn upon.

In a preferred design, the means for generating pull, especially atorsion spring, is coupled to a force transmitting member which isadapted to be wound up. The free end of the coilable force transmittingmember, such as a winding strand, is firmly connected to the push orpull rod or to the movable jaw. The torsion spring winds up the windingstrand on a winding bobbin as the movable jaw is pulled to close.

With a preferred design of the invention, a coil carrier, the abovementioned winding bobbin, is coupled in power transmitting fashion tothe means for generating pull. The coil carrier especially is supportedstationarily on the support.

With a preferred design of the invention, the means for generating pullis a coiled spiral band spring. The spiral band spring is characterizedby uniform, linear power output regardless of the degree of unwinding.The spiral band spring may comprise a spiral band carrier which issupported for rotation on the support.

With a further development of the invention, the push or pull rod isprovided with a seat for an unwound band section of the spiral bandspring. The depth of the seat is such that the unwound spiral band canlie with clearance between the push or pull rod and the support. Inunwound condition, the stored tension drive energy is stored in thespiral band spring.

With a preferred design of the invention, the drive according to theinvention is provided with a stepping gear transmission which generatessmall displacement distances and, therefore, can apply great clampingforces between the clamping jaws. The stepping gear transmission isassociated with a drive which is independent of the means for generatingpull and is actuated by an operator who actuates a drive arm. The drivearm is designed so as to be engageable, in accordance with leveragetransmission, with the push or pull rod through an entraining elementwhich is shiftable against a return spring and to be pivoted on aclamping side of the push or pull rod which side faces the jaws.

The drive according to the invention for quick locking of the movablejaw in combination with the stepping gear transmission indeed presents aone-hand vise by which rapid gripping by means of the quick-lockmechanism as well as application of great clamping forces at littlepower input can be realized.

The drive arm of the stepping gear transmission comprises a swivelbearing disposed in the course of the longitudinal direction of the pushor pull rod substantially at the level of the entraining element, thedrive arm especially having a permanent, stationary swivel bearingpoint. The swivel bearing and a force input location of the drive arm inthe entraining element are essentially located in a plane with respectto which the push or pull rod extends as a normal. The drive armespecially comprises a first portion, including an active crank which isdefined by the distance of the swivel bearing from the force inputlocation and further comprises a second portion at which an operatoractuates the drive arm. The stepping gear transmission especiallyincludes a return spring designed to move the drive arm from itsactuating positions into an output position upon release of an actuatingforce, the drive arm being actuatable for a complete actuating stroke insaid location. Furthermore, the stepping gear transmission comprisespermanent canting of the entraining element, at which canting especiallya return spring acts upon the entraining element in such a way that theentraining element abuts in canting fashion on the push or pull rod,being urged against a stop on the drive arm, when the drive arm is inthe non-actuated operating state.

A means for releasing the permanent canting of the entraining elementcan be provided as well. The means for releasing the canting of anentraining element is operable through a stop which prevents shifting ofthe push or pull rod in opposite sense to the advance direction of thestepping gear transmission.

Depending or not on the subject matters of the invention mentionedabove, the invention also relates to a clamping and/or spreading tool ofwhich the ergonomics are to be improved and, especially, anoperationally reliable and simple handle is guaranteed. Any impairing ofthe article to be clamped by forces acting from the drive on the articleis to be excluded as best as possible.

According to the invention a means for damping power output by the primemover for displacing the push or pull rod is provided at any point ofthe displacement distance of the push or pull rod on the prime mover.The damping means which is adapted to weaken the driving power to beoutput by the prime mover especially can provide uniform displacement ofthe movable jaw, the displacing rate being adjustable for simple dosingand smooth gripping of the article to be clamped. Moreover, thearrangement according to the invention comprising the prime mover andthe damping means can minimize the risk of injury at the handle of theclamping and/or spreading tool.

The ergonomics of the clamping and/or spreading tool is renderedespecially simple and advantageous if the rate of shifting is the sameat every point of the displacement distance. Such uniform speed duringdisplacement can be achieved by having the damping means tunedspecifically to the prime mover to be housed in the clamping and/orspreading tool. When a helical compression spring is used the springrates can be determined in response to the spring excursion so that adamping means adjusted accordingly can be coordinated with the helicalcompression spring.

In a particular design of the invention, the damping means and the primemover are combined in a single structural unit, especially a singlecomponent. For instance, such a component might consist of torsionspring types, especially a spiral band spring, adapted to output auniform propelling force irrespective of the spring excursion. While theelastic deformability of the torsion spring upon clamping, i.e. duringunwinding of the torsion spring provides useful power to recover theformerly wound-up original configuration, the material deformation androtational friction of the torsion spring about its support basecontribute the damping function.

In a special further development of the invention the damping means isembodied by a piston and cylinder arrangement including a damping fluid.The piston of the damping means may be secured to the push or pull rod,while the cylinder of the damping means is stationarily associated withthe support.

In a preferred design of the invention, the damping means acts on arotatable gear member. The gear member may be designed to be a dampingmember adapted to be driven in rotation and working in damping fashion,especially splashing about in a damping fluid, especially a dampingliquid contained in a casing.

The damping means may achieve its damping characteristic by generatingfriction loss. It may also be proposed according to the invention thatthe damping means should produce splashing loss.

Another aspect of the invention, dependent on or independent of thesubject matters of the invention mentioned above, relates to a clampingand/or spreading tool with which sufficient drive energy for carryingout displacements of the push or pull rod is always at the operatingperson's disposal, no matter what the operation configuration of theclamping and/or spreading tool.

According to the invention a mechanism is provided for loading driveenergy, the mechanism being chargeable independently of the displacementoperation of the push or pull rod. If an operator needs drive energywhen the drive energy reservoir is empty because the helical compressionspring is relaxed already, the measure according to the invention canput fresh drive energy at the disposal of the drive without changing theposition of the movable jaw with respect to the stationary jaw, in otherwords without having to alter the operating state of the clamping and/orspreading tool. Thus the functional flexibility of the clamping and/orspreading tool is greatly enhanced for the operator. Charging, forinstance, may be done prior to use of the clamping and/or spreading tooland then be utilized in the individual case. Moreover, according to theinvention a torsion spring is provided as the drive, and this springitself presents the reservoir of drive energy. The energy reservoir isloaded when the torsion spring is tightened. The torsion spring isespecially well suited as a reservoir for drive energy because thetorsion spring can output its propelling force in the form of rotarymotion, not requiring translatory motion which would entail considerabledemand for space, as is the case with the known clamping and/orspreading tool according to U.S. Pat. No. 6,568,667.

The torsion spring may be locked for automatic release of its driveenergy, being supported so as to be rotatable against the drivingdirection of rotation for charging by an operating member or aninterlocking clinch arrangement. The means for locking the distributionof drive energy may be a latch means. The torsion spring may be turnedmanually from outside by the operator through the actuator means,thereby becoming charged.

The actuator means also may be designed such that it may cause releaseof the locking means in addition to the manual charging movement.

Yet another dependent or independent aspect of the invention relates toa clamping and/or spreading tool with which ergonomics are to beimproved, especially the functioning for the single handed possibilityof actuating the clamping and/or spreading tool is broadened, and driveenergy is made available at almost any operating position of theclamping and/or spreading tool.

According to the invention, a mechanism is designed to load drive energyinto the reservoir not only when the push or pull rod is displaced inclosing direction—the closing direction being understood to be thedirection in which the movable jaw moves towards the stationary jaw whenthe clamping configuration of the clamping and/or spreading tool isgiven, and the closing direction also being understood to be thedirection in which the movable jaw is moved away from the stationary jawwhen the spreading configuration of the clamping and/or spreading toolis given—but also when it is displaced in opening direction opposite tothe closing direction.

The measure according to the invention makes sure that the operator hasdrive energy available not only when the movable clamping jaw is in openposition opposite the stationary jaw but also when it abuts against thestationary jaw. Making available drive energy no matter what theoperating position and configuration of the clamping and/or spreadingtool renders the clamping and/or spreading tool actuatable by one hand,both for gripping the article to be clamped and for applying greatclamping forces to the article to be clamped and also for releasing theclamped article and opening and freeing the clamped article as well asbringing the movable jaw into a starting position in which the clampingand/or spreading tool is ready for renewed use, especially for clampinganother article.

Moreover, the measure according to the invention permits drive energy tobe made available not only for a quick-lock mechanism but also for arapid opening mechanism of the clamping jaws. If different drives arebeing used for the two different directions of displacement the loadingmechanism may be designed so that a reservoir for the first drive isloaded with energy as the clamping jaws are being closed, while areservoir for the other drive is loaded with energy as the clamping jawsare being opened.

In a preferred and/or independent design of the invention the loadingmechanism comprises a gear member driven in rotation. The gear memberreceives the required torque for the charging process, for example, byestablishing friction or form-lock contact, especially roll-off contactbetween the push or pull rod and the gear member. The gear member iscoupled to a torsion spring in such manner that the rotational movementof the gear member tensions the prime mover. Where the prime mover isembodied by a torsion spring the reservoir for drive energy and a meansfor converting rotary motion of the gear member into drive energy areintegrated in one aggregate.

With a preferred design only one prime mover, especially in the form ofa torsion spring is provided for propulsion in both directions ofdisplacement. To assure the charging procedure by the loading mechanismin both directions of displacement, a rotation alternator is provided ina further development of the invention. It changes the rotationalmovement of the gear member, upon reversal of the direction ofdisplacement of the push or pull rod, into a rotational chargingmovement which is required by the means for converting the rotationalmovement. That can be accomplished, for instance, by the provision of anintermediate gear member between the rotatable gear member and the pushor pull rod. The intermediate gear member is adapted to enter intoengagement between the push or pull rod and the gear member by way of aswitching mechanism, whereby the direction of rotation is inverted.

With the further development of the invention, the rotation alternator,especially the switch means is manually operable to cause theintermediate gear member to enter into engagement with the gear member.

With a preferred further development of the invention, the rotationalternator is made automatic, i.e. it is activated when the direction ofdisplacement of the push or pull rod is changed, for example, bysubjecting the push or pull rod to external pressure or tension.

A further development of the loading mechanism according to theinvention provides blocking of the energy release. The blocking isactivated during the charging process so that the drive energyintroduced into the reservoir will not be passed out but rather bereleasable by the operator at the time the drive energy is required.

The energy release blocking preferably may be undone manually by theoperator.

A specific design of the energy release blocking is provided with alocking pawl means or a clinch locking arrangement which blocks thedrive motion of a torsion spring and, especially, may engage the gearmember or the torsion spring.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features, and properties of the invention willbecome apparent from the description below of preferred designs of theinvention with reference to the accompanying drawings, in which:

FIG. 1 a is a side elevational view of a design of a clamping and/orspreading tool, with clamping jaws in open position;

FIG. 1 b is a cross sectional view of the clamping and/or spreading jawshown in FIG. 1 a, along line A-A;

FIG. 2 is a side elevational view of another design according to theinvention of a clamping and/or spreading tool, with clamping jaws inopen position, illustrating a drive according to the invention indriving operation to open the clamping jaws;

FIG. 3 is a side elevational view of the clamping and/or spreading toolshown in FIG. 2, illustrating the drive according to the invention indriving operation to close the clamping jaws;

FIG. 4 is a side elevational view of the clamping and/or spreading toolshown in FIG. 2, illustrating a mechanism according to the invention forloading drive energy during closing movement of the jaws;

FIG. 5 is a side elevational view of the clamping and/or spreading toolshown in FIG. 2, showing a deactivated drive, illustrating the mechanismaccording to the invention for loading drive energy during openingmovement of the jaws;

FIG. 6 a is a side elevational view of another design according to theinvention of a clamping and/or spreading tool, illustrating clampingjaws in clamping state;

FIG. 6 b is a front elevational view of the clamping and/or spreadingtool shown in FIG. 6 a;

FIG. 7 a is a side elevational view of the design according to theinvention of the clamping and/or spreading tool shown in FIGS. 6 a, 6 b,illustrating an open clamping jaw configuration;

FIG. 7 b is a cross sectional view of the clamping and/or spreading toolshown in FIG. 7 a, along line B-B;

FIG. 8 a is a side elevational view of the clamping and/or spreadingtool shown in FIGS. 6 a to 7 b, illustrating an operating mode ofclosing the clamping jaws;

FIG. 8 b is a front elevational view of the clamping and/or spreadingtool shown in FIG. 8 a;

FIG. 9 a is a side elevational view of another design according to theinvention of a clamping and/or spreading tool, with clamping jaws inopen configuration;

FIG. 9 b is a top plan view of the clamping and/or spreading tool shownin FIG. 9 a;

FIG. 9 c shows an enlarged detail of area C in FIG. 9 b;

FIG. 9 d is front elevational view of the clamping and/or spreading toolshown in FIG. 9 a.

DETAILED DESCRIPTION

The preferred design of a clamping and/or spreading tool 1 illustratedin FIGS. 1 a and 1 b comprises a push or pull rod 3 movably supported ona support 5 for displacement in longitudinal direction of the rod. Thesupport 5 comprises a closed casing 7, a fixed clamping jaw 11 beingprovided at the clamping side 9 of the push or pull rod 3, diametricallyopposite a movable clamping jaw 13 which is removably attached to oneend 14 of the push or pull rod 3.

FIG. 1 a shows the clamping mode of the clamping and/or spreading tool1. The clamping and/or spreading tool 1 will be in spreading mode whenthe movable jaw 13 is secured to the opposite end 16 of the push or pullrod 3.

At the actuating side 15 of the push or pull rod 3, opposite theclamping side 9, a handle 17 is integrally fixed to the support 5 forthe clamping and/or spreading tool to be held by one hand. In addition,the support 5 carries a stepping gear transmission 19, to be explainedin greater detail below. The casing 7 of the support 5 encloses andprotects a drive 21 according to the invention composed of a torsionspring 23 which has an axis of rotation and a rotatably supported drivewheel 25 whose axis of rotation coincides with the axis of rotation ofthe torsion spring 23.

The drive wheel 25 is in power transmitting engagement with alongitudinal edge 27 of the push or pull rod 3. In FIG. 1 a the torquetransmitting engagement is obtained by friction lock between the drivewheel 25 and the push or pull rod 3.

The drive wheel 25 rests on the support 5 in such a way that engagementbetween the drive wheel 25 and the push or pull rod 3 is warranted inevery position of displacement of the push or pull rod 3. The drivewheel 25 is made of a material containing rubber, and the positioning ofthe push or pull rod 3 with respect to the drive wheel 25 is such thatbias acts between the two, generating a normal force.

With this design of a rotatable gear member in the form of a drive wheel25 and a torsion spring 23 acting as motor and energy reservoir, adriving force attempting to close the clamping jaws 11, 13 is impartedto the push or pull rod 3 in each of its displacement positions, inother words a driving force for moving the push or pull rod 3 from rightto left, as indicated by arrow S (indicating closing direction) in FIG.1 a.

The constant engagement between the drive wheel 25 and the push or pullrod 3, moreover, assures that the torsion spring 23 will be tensionedwhen the clamping jaw 13 carries out an opening movement, i.e. when thepush or pull rod 3 moves from left to right. Thus potential energysufficient for the subsequent opening procedure will be available forrenewed opening of the clamping and/or spreading tool 1.

Use of a torsion spring 23 as a prime mover is advantageous in that itmakes sure there is substantially continuous provision of torque so thatcontinuous closing operation is offered at uniform closing force andclosing speed.

The frictional force needed for torque transmission from the drive wheel25 to the push or pull rod 3 is to be adjusted, especially by the choiceof a high coefficient of friction, so that a standstill of the push orpull rod 3 will not cause the drive wheel 25 to spin. In this way it isassured that the potential energy of the torsion spring 23 will not beset free by itself because of slippage of the drive wheel 25.

The clamping and/or spreading tool described with reference to FIGS. 1 aand 1 b explicitly does not include a mechanism for charging an energyreservoir as the movable clamping jaw closes, nevertheless it is to bemade clear hereby that the mechanism according to the invention forcharging the energy reservoir upon closing of the clamping and/orspreading tool may be combined with the above designed clamping and/orspreading tools.

The design according to FIGS. 2 and 3 presents a clamping and/orspreading tool which differs from the clamping and/or spreading toolaccording to FIGS. 1 a and 1 b substantially in that an alternative formof drive according to the invention is provided for the clamping and/orspreading tool. To facilitate reading the description of the figures,identical or similar parts as in the design shown in FIGS. 1 a and 1 bwill be designated by the same reference numerals incremented by 100. Itwill not be necessary to explain the functioning of the components onceagain.

FIGS. 2 and 3 show two different drive configurations of a geartransmission of a drive according to the invention. With bothconfigurations, the drive is activated by releasing a locking pawl 131from ratchet teeth 133.

In the case of the gear configuration shown in FIG. 2 the clamping jaws111 and 113 are opened. The opening direction of the displacement of thepush and/or pull rod 103 is indicated by O.

The drive 121 according to the invention comprises a rotatable gearmember which is driven as a drive wheel 135 via a torsion spring 123.The torsion spring 123 is mounted in such a way that the rotation of thedrive wheel 135 will be clockwise.

An intermediate gear wheel 137 coupled for torque transmission with thedrive wheel 135 is turned in counterclockwise sense by the drive wheel135. By transmitting torque, the intermediate gear wheel 137 drives adriven wheel 139 designed as a gear component for converting rotarymotion into translatory motion. The driven wheel 139 enters into powertransmitting engagement with the edge 127 facing the actuating side 115of the push or pull rod 103. In view of the fact that the driven wheel139 is rotated in clockwise sense, the translatory movement imparted tothe push or pull rod 103 moves the movable jaw 113 in opening directionO away from the stationary jaw 111.

All the torque transmissions may be effected either by friction lock orby form lock realized by toothing or by a combination of both.

Next, a preferred further development of the invention will be explainedwhich relates to a mechanism for reversing the direction of displacementfrom displacement for opening, as shown in FIG. 2, to displacement forclosing and vice versa, which mode is illustrated in FIG. 3.

The mechanism for reversing the direction of displacement comprises aswitch means to be actuated by a draw-back lock. The draw-back lockserves to block shifting of the push or pull rod in opposed direction tothe advance direction of the stepping gear transmission, as indicated byarrow V. The blocking effect of the draw-back lock is achieved with theassistance of the push or pull rod 103 by canting a passage zone of arelease lever 141.

If it is intended to displace the push or pull rod 103 in openingdirection O (see FIG. 2), i.e. opposite to the advance direction V ofthe gear stepping transmission 119, on the one hand, the release lever141 must be actuated to cancel the blocking effect of the release leveracting in opening direction O due to the canting of the release lever141 on the push or pull rod 103. Actuation of the release lever 141 isnot shown in detail in FIG. 2. Slight tipping of the release lever 141is sufficient to take away the blocking effect in opening direction O.

If a change is desired from direction of displacement O to S the releaselever 141 must be pressed so hard (FIG. 3) as to activate a switch meansin the form of a press bar 143 which is displaceable in its longitudinaldirection and exerts pressure on a bearing 145 for the driven wheel 139.The bearing 145 makes sure the driven wheel 139 is shifted inlongitudinal direction, i.e. closing direction, of the push or pull rod103. Biasing means (not shown), especially a compression spring for thebearing presses the driven wheel 139 into the position illustrated inFIG. 2 where the driven wheel 139 and the intermediate gear wheel 137mesh.

Actuation of the press bar 143, in other words activation of the switchmeans causes the bearing 145 of the driven wheel 139 to be shifted sothat the driven wheel 139 will become free of the intermediate gearwheel 137 and enter into direct, torque transmitting contact with thedrive wheel 135. Having this structural design, a rotation alternator isintegrated in the drive which brings about reversal of the direction ofrotation of the drive wheel 139. In the switched state (FIG. 3) therotational movement of the drive wheel 135 driven by the torsion spring123 drives the driven wheel 139 in counterclockwise sense, whereby thepush or pull rod 103 is displaced continuously in closing direction S.

In both gear configurations shown in FIGS. 2 and 3, the drive wheel, theintermediate gear wheel, and the driven wheel all are biased in such away at their points of torque transmission that sufficient normal forceis generated to provide the frictional force required for transmittingtorque. The contact pressure which must be exerted by the driven wheel139 on the push or pull rod 103 is offered by the bias of the bearing143 in the opening mechanism according to FIG. 2. With the closingmechanism according to FIG. 3, the necessary contact pressure iswarranted by the actuating force imparted to the press bar 143 at therelease lever 141.

FIGS. 4 and 5 show a clamping and/or spreading tool 101 of which thestructure is substantially identical with that of the clamping and/orspreading tool shown in FIGS. 2 and 3. To facilitate reading thedescription of the figures, identical or similar parts will bedesignated by the same reference numerals. Identical or similar partsneed not be explained again.

The clamping and/or spreading tool 101 according to FIGS. 4 and 5differs from the clamping and/or spreading tool shown in FIGS. 2 and 3in the operating state of the drive. More specifically, the drive isdeactivated by the pawl 131 which is caught in external toothing 133 ofthe drive wheel 135, thereby blocking release of the rotational driveenergy stored in the torsion spring 123.

With this mode, the torsion spring 123 receives the rotational driveenergy required for closing and opening. Movement of the push or pullrod 103 induces counterclockwise rotational movement at the drive wheel135 through the gearing arranged between the push or pull rod 103 andthe torsion spring 123, thus tightening the torsion spring 123.

The mechanism described for reversing the direction of displacement canperform the tensioning procedure regardless of a certain direction ofdisplacement of the push or pull rod.

FIG. 4 illustrates the charging mechanism in an operational condition atwhich the torsion spring 123 is placed under tension by closing of thejaws 11, 113. As the push or pull rod 103 moves from right to left, i.e.in closing direction S, counterclockwise rotational movement is inducedin the driven wheel 139, while clockwise rotational movement is inducedin the intermediate gear wheel 137. Counterclockwise rotation of thedrive wheel 135 tightens or winds up the torsion spring incounterclockwise sense.

Since it is necessary anyway to actuate the draw-back lock by means ofthe release lever 141 in order to open the clamping jaws, i.e. formovement of the push or pull rod from left to right, full actuation ofthe release lever 141 guarantees automatically that the rotationalternator will be activated through the press bar 143 and the drivenwheel 139 will be disengaged from the intermediate gear wheel.

In this manner the drive according to the invention permits loading ofpotential energy into the drive energy reservoir, and the chargingprocedure can be performed both during opening and closing. Therefore,the torsion spring of the drive is tensioned automatically when thestepping gear transmission causes the movable jaw to approach thestationary jaw. Charging by reciprocating movements of the push or pullrod is possible.

Another design of a clamping and/or spreading tool according to theinvention with an alternative design of a drive for continuousdisplacement of a push or pull rod is presented in FIGS. 6 a, 6 b, 7 a,7 b, and 8 a, 8 b. To facilitate reading, components that are identicalor similar to the above designs are given the same reference numerals,incremented by 100 or 200. Identical or similar parts like theirfunctioning need not be explained again.

The design according to FIGS. 6 a to 8 b differs from the above designsin the embodiment of the drive. A means is provided for pulling the pushor pull rod from an open position, as shown in FIG. 7 a, into a closedposition, as shown in FIG. 6 a. In the design according to FIGS. 6 a to8 b the pulling means is embodied by a torsion spring 223 coupled to astrand 245 which is adapted to be wound up. The free end of thiscoilable strand 245 is attached to the push or pull rod 203. That isaccomplished by a fastening means 247 which is adapted to be detachedfrom the push or pull rod 203 by way of a release button 248 so as torelocate the fastening means 247 of the coilable strand 245 along thepush or pull rod 203. For example, a very long push or pull rod (notshown in the drawing) is provided in clamping and/or spreading tools forparticularly wide articles 249. In order to avoid having to use apulling means of corresponding length, the fastening means 247 may beplaced closer to the support 205.

A bobbin 251 is provided for the coilable strand 245 which is wound onthe bobbin when the clamping jaw 213 is pulled into closed position. Thecoil strand 245 extends from the bobbin 251 through a guide member 253in the vicinity of the bobbin, offset towards the movable jaw 213, toguide the coil strand 245 into a depression 255 formed in the push orpull rod 203. From the guide member 253, the coil strand 245 extendsalong the push or pull rod 203 in the depression 255 thereof to thefastening means 247.

The coil strand 245 may be in the form of a filament or a metalreinforced textile thread. Small diameter nylon strings likewise may beused as coil strand.

The push or pull rod 203 with its depression 255 to receive the coilstrand 245 is configured like an I-beam, as shown in FIG. 7 b, havingtwo lateral depressions 255. The dimensioning of the depressions is suchthat the coil strand can slide along without contacting the casing 207of the support 205.

A special inventive measure resides in associating a damping means 257,diagrammatically indicated in FIGS. 6 a, 7 a, and 8 a, with therotatably supported bobbin 251 which is coupled to the torsion spring223 so as to drive it in rotation.

The damping means 257 is designed to dampen the force acting on themovable jaw 213 under the tension exerted by the pulling means so as tomake sure a controllable closing rate of the movable jaw 213 isobtained. The desired closing rate depends on the desires of the personshandling the clamping and/or spreading tool 201. The damping means 257may be based on the principle of friction loss or splashing loss of thework fluid.

The damping means 257 is especially advantageous if a torsion springshould be used which offers non-nonlinear provision of power. In thatevent the damping means 257 may be harmonized with the torsion spring insuch manner that the power transmission becomes linear.

In the drive according to the invention shown in FIGS. 6 a to 8 b amechanism is realized for storing and loading energy by means of thetorsion spring. The torsion spring 223 contains the lowest level valuein the reservoir when the clamping jaws 211 and 213 are closed. Pullingthe clamping jaw 213 away from the stationary jaw 211 by light actuationof the release lever 241 of the draw-back lock to loosen the clampingand/or spreading tool, tightens the torsion spring 223 through the coilstrand 245. As the release lever 241 is let go, springs 259 and 261 willset the release lever 241 into a canted position with respect to thepush or pull rod 203. The frictional and tilting forces resulting withthis canted position are so great that independent closing of theclamping jaw by the pulling means is out of the question. The frictionalor tilting force needed at the release lever 241 to accomplish that canbe adjusted in consideration of the spring rate of springs 259 and 261.

When the operator actuates the release lever 241 the frictional ortilting forces at the push or pull rod are set free, whereby therotational drive energy stored in the torsion spring 223 is released andthe movable jaw is drawn towards the stationary jaw 211 by the coilstrand 245. The operating condition of closing is illustrated in FIGS. 8a and 8 b. The pulling means continues to act until the article 249 hasbeen grasped by the jaws 211, 213 (FIGS. 6 a, 6 b) and the pull of thetorsion spring 223 no longer suffices to cause further shifting of thepush or pull rod 203 in closing direction S.

Upon termination of the rapid closing process by the pulling meansaccording to the invention, great clamping forces can be imparted to thearticle 249 through the stepping gear transmission 219 of small stepwidth, to be described in greater detail below.

FIGS. 9 a to 9 d show another clamping and/or spreading tool accordingto the invention. To facilitate reading the description of the figures,identical or similar components are marked by the same referencenumerals, incremented by 100, 200, or 300. Identical or similar partsneed not be explained again.

The design of the clamping and/or spreading tool 301 according to FIGS.9 a to 9 d differs from the design of the clamping and/or spreading toolaccording to FIGS. 6 a to 8 b in that the means for pulling the movablejaw 313 on to the stationary jaw 311 is performed exclusively by meansof a torsion spring 323, in other words without using a coil strandconnecting the torsion spring with the push or pull rod 303 or themovable jaw 313.

The torsion spring 323, as designed according to FIGS. 9 a to 9 d, is aspiral band spring supported for rotation in the casing 207 of thesupport 205. The spiral band spring may be unwound so as to storerotational drive energy, the unwound portion 365 being received in thedepression 355 of the push or pull rod. For winding up the unwoundportion 365 of the spiral band, the base 367 of the spiral band springis rotatably supported on the support 305. The free end of the spiralband portion 365 which can be unwound is secured to the push or pull rod303 or to the movable jaw 313. The respective fastening means (notshown) for the spiral band portion 365 is detachable, making thefastening means relocatable along the push or pull rod 303, especiallyso as not to unwind the spiral band spring too much when the articles tobe clamped are great (not shown in the drawing).

The spiral band spring has the special advantage of imparting a uniformlinear driving force, irrespective of the distance covered, to themovable jaw 313 or to the push or pull rod 303.

The spiral band spring, therefore, fulfills both the task of a pullingmeans and that of a damping means for providing uniform closing rates.

To receive the spiral band base 367 on which the spiral band portion 365is wound, the casing 307 may include a lateral opening through which thebase 367 including the wound spiral band portion 365 may protrude, asillustrated in FIGS. 9 b and 9 c.

The closing mode as well as the actuation of the clamping and/orspreading tool 303 including the spiral band spring essentiallycorrespond to the clamping and/or spreading tool 203 which has beendescribed with reference to FIGS. 6 a to 8 b with the pulling means andcoil strand used in that case.

Both clamping and/or spreading tools described in FIGS. 6 a to 8 b andFIGS. 9 a to 9 d may be equipped with a mechanism (not shown) forloading an energy reservoir when the one-hand vise is being closed. Thiscombination of loading mechanisms is required especially when also anadditional drive is integrated in the clamping tools according to FIGS.6 a to 8 b and 9 a to 9 d, in particular to be able to displace the pushor pull rod in both longitudinal directions.

Following the closing movement of the movable jaw 313 caused by thespiral band spring, the desired great clamping force between the jaws311 and 313 can be built up by means of the stepping gear transmission319 of small step width.

Next, the structure and functioning of the stepping gear transmission ofsmall step width will be described. The stepping gear transmissionsubstantially corresponds to the one indicated by the applicant inGerman patent application DE 10335365.8.

The stepping gear transmission 19 to 319 is designed to provide poweroperation of the clamping and/or spreading tool 1 to 301 by which thepush or pull rod 3 to 303 is displaceable in small step widths infeeding direction V. During this power operation a bell crank of a drivearm 71 to 371 is effective which is defined by the distance of a swivelbearing 73 to 373 of the drive arm 71 to 371 and a power input pin 75 to375. In view of the fact that the actuating lever of the drive arm 71 to371 is much greater than the bell crank, clamping forces can begenerated which are ten times bigger than those obtainable with thestepping gear transmission disclosed in U.S. Pat. No. 6,568,667.

The compression spring 77 to 377 housed in the casing 307 constantlypresses an entraining slide element 79 to 379 against the power inputpin 75 to 375 of the drive arm 71 to 371. Moreover, the compressionspring 77 to 377 serves to move the entraining slide element 79 to 379into a constantly canted position with respect to the push or pull rod 3to 303. This is achieved due to the fact that the pressure inputlocation of the compression spring 77 to 377 is located closer to thepush or pull rod 3 to 303 than the power input pin 75 to 375, wherebythe entraining slide element 79 to 379 is swung around the power inputpin 75 to 375 in counterclockwise sense until the entraining slideelement 79 to 379 cants with respect to the push or pull rod 3 to 303.Thus it is made sure that actuation of the drive arm 71 to 371 inswinging motion around the swivel bearing 73 to 373 directly causesdisplacement of the push or pull rod, whereby clamping forces betweenthe clamping jaws 13, 15 to 313, 315 can be generated directly.Subsequent to a stroke by the drive arm 71 to 371, the operator mustrelease the latter, whereby the compression spring 77 to 377 lifts theentraining canting of the entraining slide element 79 to 379 withrespect to the push or pull rod 3 to 303 and the drive arm 71 to 371 isreturned into the starting position, shown as an example in FIG. 9 a.

The favorable leverage ratios obtained for the stepping geartransmission of small step width is realized, above all, by both theswivel bearing 73 to 373 and the power input pin 375 being placed at theclamping side 9 to 309.

The features disclosed in the specification above, in the figures andclaims may be significant to implementing the invention in the variousembodiments, both individually and in any combination. For instance,mutual exchange and combination of the various drive mechanisms arepossible. It is quite within the concept of the invention, for example,to combine the damping means (257) with torsion spring drives, asillustrated in FIGS. 1 a and 1 b or 2 to 5.

1. A clamp, comprising: a rod including a first longitudinal depression;a first jaw coupled to the rod; a second jaw coupled to the rod; and aspiral band spring rotatably mounted in the first jaw, a free end of thespiral band spring being secured to the rod, and an unwound portion ofthe spiral band spring being disposed within the first longitudinaldepression, the spiral band spring imparting a linear driving force onthe rod.
 2. A clamp according to claim 1, wherein the second jaw isremovably coupled to the rod.
 3. A clamp according to claim 1, whereinthe spiral band spring has an axis of rotation that is substantiallyperpendicular to a longitudinal axis of the rod.
 4. A clamp according toclaim 1, wherein the spiral band spring is at least partially wound on abobbin located in the first jaw.
 5. A clamp according to claim 4,wherein the bobbin is rotatably supported in the first jaw.
 6. A clampaccording to claim 1, wherein the spiral band spring is charged withpotential energy when the rod is moved relative to the first jaw.
 7. Aclamp according to claim 1, further comprising a resiliently biasedbreaking lever located in the first jaw, the breaking lever beingcoupled to a release lever that extends outside of the first jaw.
 8. Aclamp according to claim 7, further comprising a biasing element withinthe first jaw, the biasing element biasing the breaking lever to acanted position with respect to the rod, the canted position of thebreaking lever preventing movement of the rod in one direction withrespect to the first jaw.
 9. A clamp according to claim 1, wherein therod has an I-beam cross-sectional shape.
 10. A clamp according to claim1, further comprising a second longitudinal depression located on anopposite side of the rod from the first longitudinal depression.
 11. Aclamp, comprising: a push/pull rod having a first longitudinaldepression; a first jaw coupled to the push/pull rod; a second jawcoupled to the push/pull rod; and a motor rotatably mounted in the firstjaw, an unwound portion of the motor being disposed in the longitudinaldepression, and a free end of the motor being attached to the push/pullrod, the motor imparting a linear driving force to the push/pull rod.12. A clamp according to claim 11, wherein the second jaw is removablyattached to the push/pull rod.
 13. A clamp according to claim 12,wherein the motor is a spiral band spring.
 14. A clamp according toclaim 13, wherein the spiral band spring is positioned on a rotatablespool that is located within the first jaw.
 15. A clamp according toclaim 14, wherein the rotatable spool is a bobbin.
 16. A clamp accordingto claim 15, wherein the bobbin has an axis of rotation that issubstantially perpendicular to a longitudinal axis of the push/pull rod.17. A clamp according to claim 11, wherein the push/pull rod furthercomprises a second longitudinal depression located on an opposite sideof the push/pull rod from the first longitudinal depression.
 18. Amethod of manufacturing a bar clamp, comprising: providing a bar with alongitudinal depression; attaching a first jaw to the bar; attaching asecond jaw to the bar; rotatably mounting a spiral band spring in thefirst jaw; unwinding a portion of the spiral band spring and disposingthe unwound portion of the spiral band spring in the longitudinaldepression; and attaching a free end of the spiral band spring to thebar.